nupp.digest

Cryptographic hashes: SHA-256 and the rest.

One call for a whole string, or a context you feed in pieces and then consume.

const digest = nupp.digest

print(digest.hexDigest("sha256", "hello"))

local running = digest.newDigest("sha256")

running:write("hel")
running:write("lo")

print(running:hexDigest())

A context is an io.Writer, so anything that fills a writer fills a digest: reader:transferTo(running) hashes a whole file or response body without holding it.

Finalizing consumes the context, so a digest is taken once and the binding is spent afterward. Create another context to digest another message. digest() returns raw bytes, digest(destination) writes them into a writable byte span you already have, and hexDigest() returns lowercase hexadecimal. Dropping a context that was never finalized closes its provider state.

MD5 and SHA-1 are here for talking to things that already use them, and for nothing else.

A host may supply its own catalog through nupp.digest.spi, chosen by priority when this module initializes. Its entries override the built-ins of the same name, the ones it does not name stay available, and a descriptor whose size disagrees with its algorithm is refused. The catalog is read once, at load, so no context operation resolves a service.

record Algorithm ...

name: string

digestSize: integer

implementation: provider.Algorithm

newDigest: function newDigest(self): Digest

interface Digest is Writer ...

close: @nosuspend function(takes self: Digest): nil

algorithm: function(self: Digest): string

digestSize: function(self: Digest): integer

write: function(exclusive self: Digest, bytes: string): (boolean, string?)

writeSpan: function(exclusive self: Digest, borrows bytes: span.ByteSpan): (integer?, string?)

flush: function(self: Digest): (boolean, string?)

digest: function(takes self: Digest): string
& function(takes self: Digest, exclusive destination: span.ByteWriteSpan): integer

hexDigest: function(takes self: Digest): string

function algorithm(name: string): Algorithm

function algorithms(): {string}

function digest(name: string, bytes: string): string

function hexDigest(name: string, bytes: string): string

function lookup(name: string): Algorithm?

function newDigest(name: string): Digest